FY-3D/MWRI在不同轨道位置的重采样误差分析  

Analysis of resampling error of FY-3D/MWRI at different orbital positions

作　　者：张洲 王振占 何文明 佟晓林 丁甲 ZHANG Zhou;WANG Zhenzhan;HE Wenming;TONG Xiaolin;DING Jia(Key Laboratory of Microwave Remote Sensing,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China;School of Electronic,Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家空间科学中心中国科学院微波遥感技术重点实验室,北京100190 [2]中国科学院大学电子电气与通信工程学院,北京100049

出　　处：《遥感学报》2025年第1期219-231,共13页NATIONAL REMOTE SENSING BULLETIN

基　　金：国家重点研发计划(编号:2022YFB3903303)。

摘　　要：中国风云三号(FY-3)卫星是国际气象组织组网卫星之一,其搭载的微波成像仪(MWRI)可为气象研究、天气预报等多个领域提供有效数据。在应用MWRI数据进行多频率探测通道的协同反演时,必须考虑通过重采样来使不同探测频点的数据具有一致的空间分辨率。BG(Backus-Gilbert)方法是一种被广泛用于星载微波辐射计亮温数据重采样的方法。传统重采样方式应用BG方法计算辐射计单次旋转扫描得到的采样点的权重系数(预计算权重系数),并将其直接应用到所有旋转扫描获取的采样点上,进而完成全部数据的重采样。然而,在卫星仪器的采样过程中,地球椭球面等因素的影响会导致观测视场之间的相对位置发生改变,将预计算权重系数直接应用到全部数据会给重采样带来误差。因此,本文提出一种结合天线方向图投影定位方法的重采样方式,详细分析了MWRI数据在不同轨道位置的重采样效果。实验结果表明,本文采用的重采样方式能够在MWRI的不同的通道组合上修正传统重采样方式造成的平均1.32 K的亮温误差。本文指出并修正了重采样亮温的一种误差来源。未来在使用多频率探测通道数据协同反演地球物理参数时,根据反演参数对亮温变化的敏感程度,应用本文方式获取的重采样数据可以获得更准确的反演结果。The MicroWave Radiation Imager(MWRI)on China’s Fengyun-3(FY-3)satellite can provide effective data for various fields,such as meteorological research and weather forecasting.When using MWRI data for coinversion of multifrequency detection channels,considering resampling is necessary to make the data of different detection frequency points have a consistent spatial resolution.The Backus-Gilbert(BG)method is a widely used resampling method for spaceborne microwave radiometers.The traditional resampling method uses the BG method to calculate the weight coefficient of the sampling points obtained by a single rotation scan of the radiometer(precalculated weight coefficient)and directly applies it to all sampling points generated by the rotation scan,thereby completing the resampling of all data.However,during the sampling process of satellite instruments,the influence of factors such as the ellipsoid of the Earth will lead to changes in the relative positions between the observation fields,and directly applying the precalculated weight coefficients to all the data will induce errors in resampling.Therefore,in this paper,on the basis of the orbit parameters and pattern information of FY-3D MWRI,we propose a resampling method combined with antenna pattern projection positioning and analyze the resampling effect of MWRI at different orbit positions in detail.In the resampling experiments with fixed scan lines,we implement resampling for different combinations of source and target channels on the 200th scan line of the sample data.Results show that the traditional resampling method can achieve a better resampling effect by applying the BG method on a fixed scan line.In resampling experiments at different scan lines,we randomly select sample data in the time range from 2019-04-01 to 2019-12-11 and calculate the positional changes of the adjacent points in the source pattern of the 1st,44th,and 133rd scan columns with the increase in the scan lines of the sample data.The fit error due to positional changes is then calcula

关 键 词：FY-3D微波成像仪 Backus-Gilbert方法 亮温 重采样 拟合误差 空间分辨率 采样 误差分析 

分 类 号：TP722.6[自动化与计算机技术—检测技术与自动化装置] P2[自动化与计算机技术—控制科学与工程]